The present invention relates in general to the testing of cranes for loading capacity.
The testing of cranes in regard to their load weight capacity typically involves use of either one large fixed weight or a plurality of smaller individual weights. As to use of a single large fixed weight for crane testing, it was limited to testing of only one correspondingly sized crane, and imposed high loading conditions on the support floor as well as to create transport and storing problems. In regard to crane load testing by use of plural individual weights, attachment of such weights to the crane involved use of rigging gear, such as shackles and wire rope slings, for crane pick up of the weights. Cluster assembly resulted therefrom, that was very cumbersome and dangerous especially in view of varying rigging hardware lengths and distances between the crane attachment point and the respective individual weights. Often, the rigging hardware for all weights did not directly fit into the crane attachment hook, so as to create a need for intermediate rigging hardware detracting from the otherwise available crane lift height. It is therefore an important object of the present invention to provide apparatus for a more versatile method of load testing a wide variety of different types and sizes of cranes in a less cumbersome and less costly manner.
In accordance with the present invention, a crane load testing device is assembled from three basic structural components, consisting of: a generally rectangular load carrying base frame having four vertical frame posts attached thereto by welding; a pair of intermediate beams respectively adapted to be removably attached by bolts to a pair of the vertical frame posts for horizontal extension therebetween; and a main lift beam removably attachable to said pair of intermediate beams and having a pod through which attachment of the main lift beam to the crane may be effected. A plurality of relatively heavy weight loads may thereby be positioned on the base frame between its spaced frame posts, while additional weights of less weight may be vertically stacked on the base frame at outer locations thereon on the other sides of such frame posts.
The foregoing arrangement of the crane load testing device enables it to be more readily stored before transport in its disassembled condition to some desired location below a crane. In such disassembled condition of the testing device, its load carrying base frame allows the load weights to be spread out over a large area to reduce floor loading density. The main lift beam which is thereafter removably attached to complete assembly enables secure retention of load weights on the base frame as well as direct and secure transmittal of such loading on the base frame to a wide variety of cranes without entangling rigging hardware. Easy assembly and removable attachment of the main lift beam to the base frame posts through the intermediate lift beams facilitates the stacking of load weights on the base frame, including the stacking or removal of additional load weights to accommodate different loading requirements.